The present invention relates to orthopaedic implants, in particular to hip and knee prostheses, substantially involving a metallic substrate with a nitride-based ceramic coating, which is biocompatible, hypo-allergenic, wear-proof and displays a low ion release and a high adhesion. More particularly, the invention relates to orthopaedic joint substrates of Co—Cr—Mo alloys coated with niobium nitride nanolayers, and chromium nitride nanolayers, protected by at least one chromium nitride microlayer.